Method for obtaining reduced thermal flux in silicone resin composites

#1. Field of the Invention

#This invention relates to improvements in the thermal barrier properties of silicone resin/glass fiber composites. More particularly, it pertains to the use of a thermal treatment of composites comprising a polysiloxane (silicone resin) matrix with a glass or quartz fiber reinforcement embedded in such matrix in order to effect a chemical change in the structure of the composite from silicone resin into porous silicone dioxide, the latter having improved thermal barrier properties.

#2. Description of the Related Art

#The features and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where

#FIG. 1 is a cross-section of a missile nosecone which is a preferred embodiment of this invention.

#FIG. 2(a) represents a diagram schematically showing exposure of a silicone resin composite material to light radiation.

#1. The Method in General

#The method comprises three principal steps. First, a layer of a silicone resin composite material is applied onto a surface to be protected from thermal degradation. Any protected surface will experience the reduction in the thermal flux, but, as mentioned above and subsequently discussed further, such protection is especially important for organic polymeric materials, an overwhelming majority of which are relatively thermally unstable.

#Next, the surface of the silicone resin composite is coated with a layer of a highly optically absorptive material. This step is very important and is necessary when a quartz-lamp heat treatment (or other methods of heating using light radiation) is subsequently used because, without it, the method would not be viable due to poor light absorption characteristics of the silicone resin-based composites.